Structures of ciguatoxin and its congener

Ciguatoxin (CTX) is a toxic principle of ciguatera, one of the largest scale food poisonings of nonmicrobial origins, which results from eating coral reef fish. Its structure has thus become one of the most challenging targets among natural-product chemists. In the previous reports, we have presented a molecular formula, C sub(60)H sub(86)O sub(19), and a partial structure (C1-C22) of the toxin, including the stereochemistry. We report here the elucidation of the rest of the molecule (C23-C60), resulting in the determination of the planar structure of the whole molecule.